syzbot report KMSAN: uninit-value in pick_link, the root cause is that squashfs_symlink_read_folio did not check the length, resulting in folio not being initialized and did not return the corresponding error code. The length is calculated from i_size, so it is necessary to add a check when i_size is initialized to confirm that its value is correct, otherwise an error -EINVAL will be returned. Reported-and-tested-by: syzbot+24ac24ff58dc5b0d26b9@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=24ac24ff58dc5b0d26b9 Signed-off-by: Lizhi Xu <lizhi.xu@xxxxxxxxxxxxx> --- fs/squashfs/inode.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c index 16bd693d0b3a..3c667939f1d7 100644 --- a/fs/squashfs/inode.c +++ b/fs/squashfs/inode.c @@ -394,6 +394,11 @@ int squashfs_read_inode(struct inode *inode, long long ino) return -EINVAL; } + if ((int)inode->i_size < 0) { + ERROR("Wrong i_size %d!\n", inode->i_size); + return -EINVAL; + } + if (xattr_id != SQUASHFS_INVALID_XATTR && msblk->xattr_id_table) { err = squashfs_xattr_lookup(sb, xattr_id, &squashfs_i(inode)->xattr_count, -- 2.43.0
